Fix wrong truncate_prompt_tokens type hint (#22761)

Signed-off-by: Gabriel Marinho <gmarinho@ibm.com>
Signed-off-by: Gabriel Marinho <104592062+gmarinho2@users.noreply.github.com>
Signed-off-by: Max de Bayser <mbayser@br.ibm.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Max de Bayser <mbayser@br.ibm.com>

vllm/entrypoints/llm.py

@@ -51,7 +51,7 @@ from vllm.tasks import PoolingTask
 from vllm.transformers_utils.tokenizer import (AnyTokenizer, MistralTokenizer,
                                                get_cached_tokenizer)
 from vllm.usage.usage_lib import UsageContext
-from vllm.utils import Counter, Device, is_list_of
+from vllm.utils import Counter, Device, as_iter, is_list_of
 from vllm.v1.sample.logits_processor import LogitsProcessor
 
 if TYPE_CHECKING:
@@ -364,14 +364,6 @@ class LLM:
             # Use default sampling params.
             sampling_params = self.get_default_sampling_params()
 
-        tokenization_kwargs: dict[str, Any] = {}
-        truncate_prompt_tokens = None
-        if isinstance(sampling_params, SamplingParams):
-            truncate_prompt_tokens = sampling_params.truncate_prompt_tokens
-
-        _validate_truncation_size(model_config.max_model_len,
-                                  truncate_prompt_tokens, tokenization_kwargs)
-
         # Add any modality specific loras to the corresponding prompts
         lora_request = self._get_modality_specific_lora_reqs(
             prompts, lora_request)
@@ -381,7 +373,6 @@ class LLM:
             params=sampling_params,
             use_tqdm=use_tqdm,
             lora_request=lora_request,
-            tokenization_kwargs=tokenization_kwargs,
             priority=priority,
         )
 
@@ -871,6 +862,8 @@ class LLM:
                 If `False`, no progress bar is created.
             lora_request: LoRA request to use for generation, if any.
             pooling_task: Override the pooling task to use.
+            tokenization_kwargs: overrides tokenization_kwargs set in
+                pooling_params
 
         Returns:
             A list of `PoolingRequestOutput` objects containing the
@@ -916,24 +909,17 @@ class LLM:
             # Use default pooling params.
             pooling_params = PoolingParams()
 
-        if isinstance(pooling_params, PoolingParams):
-            pooling_params.verify(pooling_task, model_config)
-        else:
-            for pooling_param in pooling_params:
-                pooling_param.verify(pooling_task, model_config)
-
-        if tokenization_kwargs is None:
-            tokenization_kwargs = dict[str, Any]()
-            _validate_truncation_size(model_config.max_model_len,
-                                      truncate_prompt_tokens,
-                                      tokenization_kwargs)
+        for param in as_iter(pooling_params):
+            param.verify(pooling_task, model_config)
+            # for backwards compatibility
+            if truncate_prompt_tokens is not None:
+                param.truncate_prompt_tokens = truncate_prompt_tokens
 
         self._validate_and_add_requests(
             prompts=prompts,
             params=pooling_params,
             use_tqdm=use_tqdm,
             lora_request=lora_request,
-            tokenization_kwargs=tokenization_kwargs,
         )
 
         outputs = self._run_engine(use_tqdm=use_tqdm)
@@ -1385,7 +1371,6 @@ class LLM:
         *,
         use_tqdm: Union[bool, Callable[..., tqdm]] = True,
         lora_request: Optional[Union[Sequence[LoRARequest], LoRARequest]],
-        tokenization_kwargs: Optional[dict[str, Any]] = None,
         priority: Optional[list[int]] = None,
     ) -> None:
         if isinstance(prompts, (str, dict)):
@@ -1412,7 +1397,17 @@ class LLM:
             tqdm_func = use_tqdm if callable(use_tqdm) else tqdm
             it = tqdm_func(it, desc="Adding requests")
 
+        model_config = self.llm_engine.model_config
+
         for i, prompt in enumerate(it):
+
+            param = params[i] if isinstance(params, Sequence) else params
+
+            tokenization_kwargs: dict[str, Any] = {}
+            _validate_truncation_size(model_config.max_model_len,
+                                      param.truncate_prompt_tokens,
+                                      tokenization_kwargs)
+
             self._add_request(
                 prompt,
                 params[i] if isinstance(params, Sequence) else params,

vllm/entrypoints/openai/protocol.py

@@ -452,7 +452,7 @@ class ChatCompletionRequest(OpenAIBaseModel):
     min_tokens: int = 0
     skip_special_tokens: bool = True
     spaces_between_special_tokens: bool = True
-    truncate_prompt_tokens: Optional[Annotated[int, Field(ge=1)]] = None
+    truncate_prompt_tokens: Optional[Annotated[int, Field(ge=-1)]] = None
     prompt_logprobs: Optional[int] = None
     allowed_token_ids: Optional[list[int]] = None
     bad_words: list[str] = Field(default_factory=list)
@@ -995,7 +995,7 @@ class CompletionRequest(OpenAIBaseModel):
     min_tokens: int = 0
     skip_special_tokens: bool = True
     spaces_between_special_tokens: bool = True
-    truncate_prompt_tokens: Optional[Annotated[int, Field(ge=1)]] = None
+    truncate_prompt_tokens: Optional[Annotated[int, Field(ge=-1)]] = None
     allowed_token_ids: Optional[list[int]] = None
     prompt_logprobs: Optional[int] = None
     # --8<-- [end:completion-sampling-params]
@@ -1325,8 +1325,10 @@ class EmbeddingCompletionRequest(OpenAIBaseModel):
     # --8<-- [end:embedding-extra-params]
 
     def to_pooling_params(self):
-        return PoolingParams(dimensions=self.dimensions,
-                             normalize=self.normalize)
+        return PoolingParams(
+            truncate_prompt_tokens=self.truncate_prompt_tokens,
+            dimensions=self.dimensions,
+            normalize=self.normalize)
 
 
 class EmbeddingChatRequest(OpenAIBaseModel):
@@ -1393,8 +1395,10 @@ class EmbeddingChatRequest(OpenAIBaseModel):
         return data
 
     def to_pooling_params(self):
-        return PoolingParams(dimensions=self.dimensions,
-                             normalize=self.normalize)
+        return PoolingParams(
+            truncate_prompt_tokens=self.truncate_prompt_tokens,
+            dimensions=self.dimensions,
+            normalize=self.normalize)
 
 
 EmbeddingRequest = Union[EmbeddingCompletionRequest, EmbeddingChatRequest]
@@ -1430,7 +1434,9 @@ class ScoreRequest(OpenAIBaseModel):
     # --8<-- [end:score-extra-params]
 
     def to_pooling_params(self):
-        return PoolingParams(activation=self.activation)
+        return PoolingParams(
+            truncate_prompt_tokens=self.truncate_prompt_tokens,
+            activation=self.activation)
 
 
 class RerankRequest(OpenAIBaseModel):
@@ -1460,7 +1466,9 @@ class RerankRequest(OpenAIBaseModel):
     # --8<-- [end:rerank-extra-params]
 
     def to_pooling_params(self):
-        return PoolingParams(activation=self.activation)
+        return PoolingParams(
+            truncate_prompt_tokens=self.truncate_prompt_tokens,
+            activation=self.activation)
 
 
 class RerankDocument(BaseModel):
@@ -1618,7 +1626,9 @@ class ClassificationRequest(OpenAIBaseModel):
     # --8<-- [end:classification-extra-params]
 
     def to_pooling_params(self):
-        return PoolingParams(activation=self.activation)
+        return PoolingParams(
+            truncate_prompt_tokens=self.truncate_prompt_tokens,
+            activation=self.activation)
 
 
 class ClassificationData(OpenAIBaseModel):

vllm/entrypoints/openai/serving_chat.py

@@ -237,7 +237,6 @@ class OpenAIServingChat(OpenAIServing):
                     documents=request.documents,
                     chat_template_kwargs=request.chat_template_kwargs,
                     tool_parser=tool_parser,
-                    truncate_prompt_tokens=request.truncate_prompt_tokens,
                     add_special_tokens=request.add_special_tokens,
                 )
             else:

vllm/entrypoints/openai/serving_classification.py

@@ -61,7 +61,6 @@ class ClassificationMixin(OpenAIServing):
                 ctx.request,
                 ctx.tokenizer,
                 ctx.request.input,
-                truncate_prompt_tokens=ctx.request.truncate_prompt_tokens,
             )
 
             return None
@@ -157,18 +156,6 @@ class ServingClassification(ClassificationMixin):
 
         return await super().handle(ctx)  # type: ignore
 
-    @override
-    def _validate_request(
-        self,
-        ctx: ClassificationServeContext,
-    ) -> Optional[ErrorResponse]:
-        if error := super()._validate_request(ctx):
-            return error
-
-        ctx.truncate_prompt_tokens = ctx.request.truncate_prompt_tokens
-
-        return None
-
     @override
     def _create_pooling_params(
         self,

vllm/entrypoints/openai/serving_completion.py

@@ -137,7 +137,6 @@ class OpenAIServingCompletion(OpenAIServing):
                 request,
                 tokenizer,
                 request.prompt,
-                truncate_prompt_tokens=request.truncate_prompt_tokens,
                 add_special_tokens=request.add_special_tokens,
             )
         except ValueError as e:

vllm/entrypoints/openai/serving_embedding.py

@@ -97,7 +97,6 @@ class EmbeddingMixin(OpenAIServing):
                     # so there is no need to append extra tokens to the input
                     add_generation_prompt=False,
                     continue_final_message=False,
-                    truncate_prompt_tokens=ctx.truncate_prompt_tokens,
                     add_special_tokens=ctx.request.add_special_tokens,
                 )
             else:
@@ -106,7 +105,6 @@ class EmbeddingMixin(OpenAIServing):
                      ctx.request,
                      tokenizer,
                      ctx.request.input,
-                     truncate_prompt_tokens=ctx.truncate_prompt_tokens,
                      add_special_tokens=ctx.request.add_special_tokens,
                  )
             return None
@@ -631,18 +629,6 @@ class OpenAIServingEmbedding(EmbeddingMixin):
 
         return await super().handle(ctx)  # type: ignore
 
-    @override
-    def _validate_request(
-        self,
-        ctx: ServeContext[EmbeddingRequest],
-    ) -> Optional[ErrorResponse]:
-        if error := super()._validate_request(ctx):
-            return error
-
-        ctx.truncate_prompt_tokens = ctx.request.truncate_prompt_tokens
-
-        return None
-
     @override
     def _create_pooling_params(
         self,

vllm/entrypoints/openai/serving_engine.py

@@ -165,7 +165,6 @@ class ServeContext(RequestProcessingMixin, ResponseGenerationMixin, BaseModel,
 
     # Shared across most requests
     tokenizer: Optional[AnyTokenizer] = None
-    truncate_prompt_tokens: Optional[Annotated[int, Field(ge=1)]] = None
 
     # `protected_namespaces` resolves Pydantic v2's warning
     # on conflict with protected namespace "model_"
@@ -297,14 +296,12 @@ class OpenAIServing:
         truncate_prompt_tokens = getattr(ctx.request, "truncate_prompt_tokens",
                                          None)
 
-        if truncate_prompt_tokens is not None:
-            if truncate_prompt_tokens <= self.max_model_len:
-                ctx.truncate_prompt_tokens = truncate_prompt_tokens
-            else:
-                return self.create_error_response(
-                    "truncate_prompt_tokens value is "
-                    "greater than max_model_len."
-                    " Please, select a smaller truncation size.")
+        if truncate_prompt_tokens is not None and \
+            truncate_prompt_tokens > self.max_model_len:
+            return self.create_error_response(
+                "truncate_prompt_tokens value is "
+                "greater than max_model_len."
+                " Please, select a smaller truncation size.")
         return None
 
     def _create_pooling_params(
@@ -528,7 +525,6 @@ class OpenAIServing:
         request: AnyRequest,
         prompt: str,
         tokenizer: AnyTokenizer,
-        truncate_prompt_tokens: Optional[Annotated[int, Field(ge=-1)]],
         add_special_tokens: bool,
     ) -> TextTokensPrompt:
         async_tokenizer = self._get_async_tokenizer(tokenizer)
@@ -538,6 +534,9 @@ class OpenAIServing:
                     "do_lower_case", False)):
             prompt = prompt.lower()
 
+        truncate_prompt_tokens = getattr(request, "truncate_prompt_tokens",
+                                         None)
+
         if truncate_prompt_tokens is None:
             encoded = await async_tokenizer(
                 prompt, add_special_tokens=add_special_tokens)
@@ -565,8 +564,10 @@ class OpenAIServing:
         request: AnyRequest,
         prompt_ids: list[int],
         tokenizer: Optional[AnyTokenizer],
-        truncate_prompt_tokens: Optional[Annotated[int, Field(ge=1)]],
     ) -> TextTokensPrompt:
+        truncate_prompt_tokens = getattr(request, "truncate_prompt_tokens",
+                                         None)
+
         if truncate_prompt_tokens is None:
             input_ids = prompt_ids
         elif truncate_prompt_tokens < 0:
@@ -652,7 +653,6 @@ class OpenAIServing:
         request: AnyRequest,
         tokenizer: AnyTokenizer,
         prompt_input: Union[str, list[int]],
-        truncate_prompt_tokens: Optional[Annotated[int, Field(ge=-1)]] = None,
         add_special_tokens: bool = True,
     ) -> TextTokensPrompt:
         """
@@ -664,7 +664,6 @@ class OpenAIServing:
                 request,
                 tokenizer,
             [prompt_input],
-                truncate_prompt_tokens=truncate_prompt_tokens,
                 add_special_tokens=add_special_tokens,
         ):
             return result
@@ -675,7 +674,6 @@ class OpenAIServing:
         request: AnyRequest,
         tokenizer: AnyTokenizer,
         prompt_inputs: Iterable[Union[str, list[int]]],
-        truncate_prompt_tokens: Optional[Annotated[int, Field(ge=-1)]] = None,
         add_special_tokens: bool = True,
     ) -> AsyncGenerator[TextTokensPrompt, None]:
         """
@@ -689,7 +687,6 @@ class OpenAIServing:
                     request,
                     prompt=prompt,
                     tokenizer=tokenizer,
-                    truncate_prompt_tokens=truncate_prompt_tokens,
                     add_special_tokens=add_special_tokens,
                 )
             else:
@@ -697,7 +694,6 @@ class OpenAIServing:
                     request,
                     prompt_ids=prompt,
                     tokenizer=tokenizer,
-                    truncate_prompt_tokens=truncate_prompt_tokens,
                 )
 
     async def _tokenize_prompt_input_or_inputs_async(
@@ -706,7 +702,6 @@ class OpenAIServing:
         tokenizer: Optional[AnyTokenizer],
         input_or_inputs: Optional[Union[str, list[str], list[int],
                                         list[list[int]]]],
-        truncate_prompt_tokens: Optional[Annotated[int, Field(ge=-1)]] = None,
         add_special_tokens: bool = True,
     ) -> tuple[list[TextTokensPrompt], list[EmbedsPrompt]]:
         """
@@ -719,6 +714,12 @@ class OpenAIServing:
         inputs_embeds = list[EmbedsPrompt]()
         inputs_text = list[TextTokensPrompt]()
 
+        truncate_prompt_tokens = getattr(request, "truncate_prompt_tokens",
+                                         None)
+
+        if (truncate_prompt_tokens or 0) < 0:
+            truncate_prompt_tokens = self.max_model_len
+
         if (isinstance(request, CompletionRequest)
                 and request.prompt_embeds is not None):
             inputs_embeds.extend(
@@ -748,14 +749,10 @@ class OpenAIServing:
                     request,
                     prompt_input["content"],
                     tokenizer=tokenizer,
-                    truncate_prompt_tokens=truncate_prompt_tokens,
                     add_special_tokens=add_special_tokens)
             else:
                 task = self._normalize_prompt_tokens_to_input(
-                    request,
-                    prompt_input["content"],
-                    tokenizer=tokenizer,
-                    truncate_prompt_tokens=truncate_prompt_tokens)
+                    request, prompt_input["content"], tokenizer=tokenizer)
             tasks.append(task)
 
         # Wait for all tokenization tasks to complete
@@ -772,7 +769,6 @@ class OpenAIServing:
                        TokenizeCompletionRequest],
         tokenizer: Optional[AnyTokenizer],
         input_or_inputs: Union[str, list[str], list[int], list[list[int]]],
-        truncate_prompt_tokens: Optional[Annotated[int, Field(ge=-1)]] = ...,
         add_special_tokens: bool = ...,
     ) -> tuple[list[TextTokensPrompt], list[EngineTokensPrompt]]:
         ...
@@ -784,7 +780,6 @@ class OpenAIServing:
         tokenizer: Optional[AnyTokenizer],
         input_or_inputs: Optional[Union[str, list[str], list[int],
                                         list[list[int]]]],
-        truncate_prompt_tokens: Optional[Annotated[int, Field(ge=-1)]] = ...,
         add_special_tokens: bool = ...,
     ) -> tuple[list[Union[TextTokensPrompt, EmbedsPrompt]], list[Union[
             EngineTokensPrompt, EngineEmbedsPrompt]]]:
@@ -796,7 +791,6 @@ class OpenAIServing:
         tokenizer: Optional[AnyTokenizer],
         input_or_inputs: Optional[Union[str, list[str], list[int],
                                         list[list[int]]]],
-        truncate_prompt_tokens: Optional[Annotated[int, Field(ge=-1)]] = None,
         add_special_tokens: bool = True,
     ) -> tuple[Union[list[TextTokensPrompt], list[Union[
             TextTokensPrompt, EmbedsPrompt]]], Union[
@@ -813,7 +807,6 @@ class OpenAIServing:
              request,
              tokenizer,
              input_or_inputs,
-             truncate_prompt_tokens=truncate_prompt_tokens,
              add_special_tokens=add_special_tokens,
          )
 
@@ -866,7 +859,6 @@ class OpenAIServing:
         documents: Optional[list[dict[str, str]]] = None,
         chat_template_kwargs: Optional[dict[str, Any]] = None,
         tool_parser: Optional[Callable[[AnyTokenizer], ToolParser]] = None,
-        truncate_prompt_tokens: Optional[Annotated[int, Field(ge=1)]] = None,
         add_special_tokens: bool = False,
     ) -> tuple[list[ConversationMessage], Sequence[RequestPrompt],
                list[EngineTokensPrompt]]:
@@ -941,7 +933,6 @@ class OpenAIServing:
                 request,
                 tokenizer,
                 request_prompt,
-                truncate_prompt_tokens=truncate_prompt_tokens,
                 add_special_tokens=add_special_tokens,
             )
         else:

vllm/entrypoints/openai/serving_pooling.py

@@ -120,7 +120,6 @@ class OpenAIServingPooling(OpenAIServing):
                     # so there is no need to append extra tokens to the input
                     add_generation_prompt=False,
                     continue_final_message=False,
-                    truncate_prompt_tokens=truncate_prompt_tokens,
                     add_special_tokens=request.add_special_tokens,
                 )
             else:
@@ -129,7 +128,6 @@ class OpenAIServingPooling(OpenAIServing):
                      request,
                      tokenizer,
                      request.input,
-                     truncate_prompt_tokens=truncate_prompt_tokens,
                      add_special_tokens=request.add_special_tokens,
                  )
         except (ValueError, TypeError, jinja2.TemplateError) as e:

vllm/entrypoints/openai/serving_score.py

@@ -266,12 +266,14 @@ class ServingScores(OpenAIServing):
         request: Union[ScoreRequest, RerankRequest],
         request_id: str,
         raw_request: Optional[Request] = None,
-        truncate_prompt_tokens: Optional[int] = None,
     ) -> Union[list[PoolingRequestOutput], ErrorResponse]:
         lora_request = self._maybe_get_adapters(request)
 
         tokenizer = await self.engine_client.get_tokenizer(lora_request)
 
+        truncate_prompt_tokens = getattr(request, "truncate_prompt_tokens",
+                                         None)
+
         tokenization_kwargs: dict[str, Any] = {}
         _validate_truncation_size(self.max_model_len, truncate_prompt_tokens,
                                   tokenization_kwargs)
@@ -343,7 +345,6 @@ class ServingScores(OpenAIServing):
                 request,
                 request_id,
                 raw_request,
-                request.truncate_prompt_tokens,
             )
             if isinstance(final_res_batch, ErrorResponse):
                 return final_res_batch
@@ -391,7 +392,6 @@ class ServingScores(OpenAIServing):
                 request,
                 request_id,
                 raw_request,
-                request.truncate_prompt_tokens,
             )
             if isinstance(final_res_batch, ErrorResponse):
                 return final_res_batch

vllm/inputs/preprocess.py

@@ -346,6 +346,22 @@ class InputPreprocessor:
     ) -> EmbedsInputs:
         return self._process_embeds(parsed_content)
 
+    def _truncate_inputs(
+            self,
+            inputs: list[int],
+            tokenization_kwargs: Optional[dict[str, Any]] = None) -> list[int]:
+
+        if not tokenization_kwargs or "truncation" not in \
+                tokenization_kwargs or self.tokenizer is None:
+            return inputs
+
+        max_length = tokenization_kwargs["max_length"]
+
+        if self.tokenizer.truncation_side == "left":
+            return inputs[-max_length:]
+        else:
+            return inputs[:max_length]
+
     def _process_tokens(
         self,
         parsed_content: TokensPrompt,
@@ -354,7 +370,8 @@ class InputPreprocessor:
         *,
         mm_hash_overrides: Optional[dict[str, list[str]]] = None,
     ) -> Union[TokenInputs, MultiModalInputs]:
-        prompt_token_ids = parsed_content["prompt_token_ids"]
+        prompt_token_ids = self._truncate_inputs(
+            parsed_content["prompt_token_ids"], tokenization_kwargs)
 
         inputs: Union[TokenInputs, MultiModalInputs]
         if multi_modal_data := parsed_content.get("multi_modal_data"):
@@ -382,7 +399,8 @@ class InputPreprocessor:
         *,
         mm_hash_overrides: Optional[dict[str, list[str]]] = None,
     ) -> Union[TokenInputs, MultiModalInputs]:
-        prompt_token_ids = parsed_content["prompt_token_ids"]
+        prompt_token_ids = self._truncate_inputs(
+            parsed_content["prompt_token_ids"], tokenization_kwargs)
 
         inputs: Union[TokenInputs, MultiModalInputs]
         if multi_modal_data := parsed_content.get("multi_modal_data"):

vllm/pooling_params.py

@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 from copy import deepcopy
-from typing import TYPE_CHECKING, Any, Optional
+from typing import TYPE_CHECKING, Annotated, Any, Optional
 
 import msgspec
 
@@ -27,6 +27,11 @@ class PoolingParams(
                     the classification outputs.
         softmax: Whether to apply softmax to the reward outputs.
     """
+    truncate_prompt_tokens: Optional[Annotated[int,
+                                               msgspec.Meta(ge=-1)]] = None
+    """If set to -1, will use the truncation size supported by the model. If
+    set to an integer k, will use only the last k tokens from the prompt
+    (i.e., left truncation). If set to `None`, truncation is disabled."""
 
     ## for embeddings models
     dimensions: Optional[int] = None

vllm/sampling_params.py

@@ -182,7 +182,8 @@ class SamplingParams(
     optionally prompt tokens as a first argument."""
     include_stop_str_in_output: bool = False
     """Whether to include the stop strings in output text."""
-    truncate_prompt_tokens: Optional[Annotated[int, msgspec.Meta(ge=1)]] = None
+    truncate_prompt_tokens: Optional[Annotated[int,
+                                               msgspec.Meta(ge=-1)]] = None
     """If set to -1, will use the truncation size supported by the model. If
     set to an integer k, will use only the last k tokens from the prompt
     (i.e., left truncation). If set to `None`, truncation is disabled."""
@@ -241,7 +242,8 @@ class SamplingParams(
         spaces_between_special_tokens: bool = True,
         logits_processors: Optional[list[LogitsProcessor]] = None,
         truncate_prompt_tokens: Optional[Annotated[int,
-                                                   msgspec.Meta(ge=1)]] = None,
+                                                   msgspec.Meta(
+                                                       ge=-1)]] = None,
         output_kind: RequestOutputKind = RequestOutputKind.CUMULATIVE,
         guided_decoding: Optional[GuidedDecodingParams] = None,
         logit_bias: Optional[Union[dict[int, float], dict[str, float]]] = None,
@@ -411,9 +413,11 @@ class SamplingParams(
             raise ValueError(f"prompt_logprobs must be non-negative, got "
                              f"{self.prompt_logprobs}.")
         if (self.truncate_prompt_tokens is not None
-                and self.truncate_prompt_tokens < 1):
-            raise ValueError(f"truncate_prompt_tokens must be >= 1, "
-                             f"got {self.truncate_prompt_tokens}")
+                and (self.truncate_prompt_tokens == 0
+                     or self.truncate_prompt_tokens < -1)):
+            raise ValueError(
+                f"truncate_prompt_tokens must be an integer >= 1 or -1, "
+                f"got {self.truncate_prompt_tokens}")
         assert isinstance(self.stop_token_ids, list)
         if not all(isinstance(st_id, int) for st_id in self.stop_token_ids):
             raise ValueError(f"stop_token_ids must contain only integers, "

vllm/transformers_utils/tokenizer_group.py

@@ -23,6 +23,7 @@ class TokenizerGroup:
         self.tokenizer_config = tokenizer_config
         self.enable_lora = enable_lora
         self.max_input_length = max_input_length
+        self.truncation_side = tokenizer_config.get("truncation_side", "left")
         self.tokenizer = get_tokenizer(self.tokenizer_id, **tokenizer_config)
         max_loras = tokenizer_config.get("max_loras", 0)
         self.lora_tokenizers = LRUCache[int, AnyTokenizer](

vllm/utils/__init__.py

@@ -1328,6 +1328,12 @@ def as_list(maybe_list: Iterable[T]) -> list[T]:
     return maybe_list if isinstance(maybe_list, list) else list(maybe_list)
 
 
+def as_iter(obj: Union[T, Iterable[T]]) -> Iterable[T]:
+    if isinstance(obj, str) or not isinstance(obj, Iterable):
+        obj = [obj]
+    return obj
+
+
 # `collections` helpers
 def is_list_of(
     value: object,